Hand-piece chuck



INVENTOR. M/on 5. Lundsen A TTORNE Y M. s. LUNDSTEN HAND-PIECE CHUCK Filed Aug. 20, 1945 Feb. l, 1949.

Patented Feb. l, 1949 NITED STATES PT Fifi aisooz Y HAND-PIECE CHUCK Milton S. Lundsten, United States Navy Application August 20, 1945 Serial No. 611,675

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 G. 757) 6 Claims.

This invention relates to iiexible shaft handpieces and more particularly to improvements in the collet chuck carried by said flexible handpieces.

An object of this invention is to provide an improved collet chuck for a flexible shaft handpiece.

Another object is to provide a collet chuck that will not require a wrench for tightening said chuck.

Another object is to provide a collet chuck that will afford greater rigidity to the rotating tool held by said collet chuck.

Another object is to provide easy accessibility to that portion of the chuck that holds the collet.

Further objects and advantages of this invention, as well as its construction, arrangement and operation, will be apparent from the following description and claims in connection with the accompanying drawing, in which,

Fig. 1 is a central longitudinal section through a collet chuck embodying one form of the pres ent invention,

Fig. 2 is a cross section taken along the line 2-2 of Fig. 1, and

Fig. 3 is a cross section taken along the line 3 3 of Fig. 1.

A cylindrical housing Il! which is open at its top has a narrow central opening at the bottom. said central opening serving as a passageway for a ilexible steel housing I I which houses a iiexible steel cable I2. The widened portion I3 of the flexible steel housing II serves to prevent slippage of housing I I from said central opening and also serves to center the exible steel cable I2 within the housing I0.

A cable fitting is at the tip of the steel cable I2 threadingly engages a central shaft I5. A seal I5 supports a ball bearing Il', the shoulder lil of said seal IE urging a coiled spring I9 against the top rim of the widened portion I3 when pressure is exerted downward upon the bearing Il. An inner bearing spacer surrounds the central shaft I5 and another similar spacer 2| separates the outer races of the ball bearings I'I. A seal 22 rides atop of the upper bearing l'l.

A locking ring 23 threadingly engages the ton inner Wall of the open portion of the housing IIJ and keeps all the elements below it in intimate contact with other immediately adjacent ele ments. A coiled spring 24 .rides atop of seal 22 while the top of said coiled spring abuts against the underside of a lockingr Spider 25. The locking ring 23 has channels 26 cut at spaced intervalslnto the Wall of the upper portion of the locking ring 23 so that the arrnsV 2l ci the locking spider 25 can fall into these channels 25 and engage the locknut 23.

The locking spider 25 has internal splines 2S at spaced intervals `along its inner periphery, said internal splines 2t 'engaging the external splines 29 on the shaft I5 when the sliding sleeve 3B is pulled out from the front housing 3i that threadingly engages the outer periphery of the locking ring 23. The shoulder 32 at the base of the sliding sleeve 3! impinges against the protruding lip 33 of the front housing SI and prevents further upward movement of the sliding sleeve 3l).

A shoulder 34 on the shaft I5 limits the upward movement of the locking spider 25. The collet 35 slips into a central opening in the top of the shaft I5, the central opening conforming substantially to the taper of the front end of said collet 35. The collet collar or head is screwed onto the shaft I5, the pressure of the inner face of the collet head upon the top face oi the collet 35 increasing the grip of the collet 35 about a mandrel in said collet 35.

A single-coil expansion spring 38 lies in a groove 39 cut into the inner Wall of the forward portion of the front housing 3l. The single-coil expansion spring 38 acts as a locking means for the sliding sleeve 36. Two similar grooves si? and il are cut in the outer wall of the sliding sleeve 3&3. By gripping the knurled face of the sliding sleeve 3d and pulling outwardly on said sliding sleeve 3d, the forward groove 40 of the sliding sleeve 3B is disengaged from the spring 3S the rear groove 4I of the sliding sleeve 3i) snaps onto the single-coil expansion spring 3i! elements 3Q and 3l thus constitute an extensible headpiece, When the sliding sleeve 3S is urged downward, rear groove 4I is disengaged from the spring 38 and the forward groove t snaps onto the spring t3. The spring 38 constantly remains in the groove 39. There are internal splines d2 on the sliding sleeve 3d and external splines d3 on the collet head 35, the purpose of which will he clarified in the description of the operation of this In operation, a mandrel cr a tool on a spindle is removed from the handpiece chuck by gripping the knurled knob of the sliding sieeve and pulling the latter outwardly from the front housing 3| so that the internal splines l2 of said slide sleeve engage the external splines e3 ci the collet head 36; the turning oi the sliding sieeve 3l! causes the collet head 35 partly to unseres' itself from the shaft l5, lecsening the grip e *he collet about said mandrel or tool. The curing of a mandrel or tool to the chuck is the reverse process. The sliding sleeve 30 is initially extended, the collet head 36 is turned by turning said sleeve 3% and tightening the grip of the collet 35 about said tool, then pushing said sliding sleeve Se into said front housing 3i when said tool or mandrel has been gripped tightly by the collet 35.

The replacement of the collet 35 with a different-size collet can be accomplished in two ways.

In one way, the knurled face of front housing 3i can be gripped and turned with one hand while the housing iii is held in the other hand until the front housing 3! is removed from the handpiece. By turning the front housing 3i, the internal splines 42 of the sliding sleeve 3i] engage the external splines 43 of the collet 35 causing the latter to come off with the front housing 3 l The collet 35 is replaced and the front housing 3i with the sliding sleeve 39 already pushed into said front housing 3i is screwed into the locking ring 23.

The other and preferred manner of removing the collet 35 consists of pulling out the sliding sleeve 3i! so that it is in an extended state, then turning said sliding sleeve 30 until the collet head 36 is completely7 unscrewed or disengaged from the shaft l5 so as to permit said collet 35 to be withdrawn the chuck; the collet 35 is replaced, the collet head 35 is re-inserted into the sliding sleeve 30; an initial turn or two of the partly knurled collet head 36 threadingly engages said collet head 3S to the shaft l5; and the turning of the sliding sleeve 3Q further threads the collet head 35 onto the shaft l5. When the collet head 35, now holding a mandrel, is completely threaded onto the shaft l5, the sliding sleeve Eil is pushed into the front housing 3l and the chuck is ready for use.

As the sleeve 30 is in its extended position, the shaft i5 is locked, the arms 2l of the locking spider 25 engaging the channels 26 of the locking spider 25 and the internal splines 28 of the locking ring 25 engaging the external splines 29 of the shaft l5, thus permitting the collet head to be tightened onto a non-rotating or temporarily locked shaft i5.

The present invention, an embodiment of which is shown in the drawings, provides many advantageous and desirable features. The presence of the upper bearings il close to the collet head 36 considerably reduces chattering of the shaft l5. The construction of the handpiece chuck in the manner shown permits this advantageous positioning of the bearings il. Greater rigidity is further accomplished by having a relatively long collet 35 and a firm collet head 36 for tightening the grip of said collet 35 about a mandrel.

The collet 35 can be easily and readily changed i factured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereonv or therefor.

What is claimed is:

l. In a handpiece chuck, a housing, a colletsupporting rotatable shaft secured in said housing, a shaft-engaging spider slidably mounted on said shaft, partly cutout locking means secured to the forward portion of said housing, an extensible headpiece detachably mounted on said locking means, resilient means for urging said spider into rotation-preventing engagement with said shaft, means on said extensible headpiece for preventing engagement of said spider with said shaft, a collet collar detachably secured to the forward tip of said shaft, and engaging means on said extensible headpiece for aiding in the positioning of said collet collar onto said shaft.

2. In a handpiece chuck, a housing, a colletsupporting splined rotatable shaft secured in said housing, an extensible headpiece detachably secured to said housing so that the outer surface of said headpiece is continuous with the outer surface of said housing, locking means slidably mounted on said splined shaft, resilient means for urging said locking means onto said splines so as to prevent rotation of said shaft with respect to said housing, a collet collar engaging the forward tip of said collet supporting shaft, means on said extensible headpiece for disengaging said shaft from its locked engagement with said housing, and further means on said extensible headwithout disturbing many parts of the chuck and without going too deeply into the chuck. This simple way of changing the collet manually, without the need of a wrench, is a timesaver in that it eliminates the need to search for wrenches which often have become misplaced. Also, by providing easy accessibility to the collet 35 the present device eliminates undue and time-wasting disassembling of the chuck.

There are no rotating parts of the chuck exposed when in use, thus avoiding inadvertent stopping of the shaft i5 when the latter is in motion. This is very important when ne machining is being done and it is necessary to have a clean sharp cut in or good contact with a material being milled, ground or polished. Moreover, the chuck can be held so that the fingers of the operator using the chuck are close to the very edge of piece for positioning said collet collar onto or removing said collet collar from said shaft.

3. In a handpiece chuck, a housing having an open end, a collet-supporting shaft secured in said housing, bearing means for said shaft, locking means engaging the housing at its open end and being adapted to assist in maintaining said bearing means at a xed distance along said shaft, splines on said shaft, an extensible headpiece secured to said locking means, a spider lock slidably mounted on said shaft, channels in said locking means to engage the arms of said spider lock, resilient means for urging said spider lock to engage said splines on said shaft while the arms of said spider lock lie in the channels of said locking means, means on said extensible headpiece for disengaging said spider lock from the splines on said shaft when said secured extensible headpiece is in its non-extended. state, a `collet collar on said collet supporting shaft, and engaging means on said extensible headpiece for aiding in the positioning of said collet collar onto said shaft.

4. In a handpiece chuck, a housing, a rotatable and frontally hollow shaft secured in said housing, locking means detachably secured near the forward end of said hou-sing, said locking means surrounding the rotating shaft and urging all the parts below it that encircle said shaft in intimate contact with one another, a readily detachable extensible headpiece secured to said locking means, the non-extensible outside wall of said headpiece being flush. with the outside wall of said housing, splines on said shaft, a locking spider mounted on said shaft and urgeable towards or away from said splines, keyways on said locking means to engage the arms of said locking spider, a collet collar on the forward portion of said shaft, and engaging means on said collet collar engageable by the extended portion of said extensible headpiece, said engagement serving to remove or secure said collet collar to said shaft depending upon the motion of said extended portion with respect to said shaft.

5. A handpiece chuck comprising a hollow housing, a exible power driven cable having a collet supporting shaft secured thereto, external splines on said shaft, a bearing and oil seal near one end of said shaft, another bearing and oil seal near the other end of said shaft, spacer elements separating said bearings, resilient means for urging said bearings and seals into intimate contact with said spacer elements to form a rigid bearing support for said shaft, a locknut engaging the forward portion of said hollow housing, a spider member slidably mounted on said shaft, the arms of said spider member engaging said locknut, an extensible headpiece secured to said locknut so that the outer surface of said extensible headpiece is continuous with the outer surface of said hollow housing, internal splines on said spider member, resilient means for urging said spider member so that the internal splines of said spider member engage the external splines of said shaft while the arms of said spider member engage said locknut, a collet collar on said shaft, means on said extensible headpiece for disengaging said spider member from the splines of said shaft, and fur* ther means on said extensible headpiece for positioning said collet collar onto said shaft or re moving said collet collar from said shaft.

6. In a handpiece chuck a rotatable shaft adapted to receive a collet, a collet collar, means adapted at one time to hold said shaft rotatably ixed and at another time to permit said shaft to rotate and means adapted simultaneously to position said collar with respect to said shaft and to cause the first-mentioned means to hold said shaft rotatably fixed, the second-mentioned means being also adapted simultaneously to be free from reaction with said collar and to cause the rst-mentioned means to permit said shaft to rotate.

MILTON S. LUNDSTEN.

REFERENCES CITED The following references are of record in the die of this patent:

UNITED STATES PATENTS Number Name Date 1,850,297 Volz Mar. 22, 1932 2,286,292 Mall June 16, 1942 

